21 tooth gearbox sprocket

[chrisk]

Suspected that might be the case. Looking the goods there, Phil - very purposeful. Might have to do some calcs on gearing before I go the 20T. You going to run 520 o-ring or non-o-ring?

There's a spread sheet I have I can sell you

 

[phil37]

You going to run 520 o-ring or non-o-ring?

I'm running non O ring as i need as much clearance on the  monoshock mounting swinger loop as i can get - as this bike is a one-off prototype - i would have changed the loop configuration on production runs.  I'm doing a load of "snagging" ATM and will (hopefully) spot all the niggling problems before they become an issue. Unfortunately the cush mounting doesn't allow me to fit any smaller rear sprocket.  - Regards - Phil